Circuit breaker unit



April 1934. A. s. CASWELL 1,954,583

CIRCUIT BREAKER UNIT Filed July 22, 1931 5 Sheets-Sheet l I N VEN TOR.

MAKW

L ATTORNEY.

April 10, 1934.

A. S. CASWELL CIRCUIT BREAKER UNIT Filed July 22, 1931 5 Sheets-Sheet 27Q? ATTORNEY.

April 10, 1934. A. s. CASWELL CIRCUIT BREAKER UNIT Filed July 22, 1931 5Sheets-Sheet 3 v INVENTOR. I

1 ATTORNEY.

April. 1934- A. s. CASWELL 1,954,583

CIRCUIT BREAKER UNIT Filed July 1931 5 Sheets-Sheet 4 IN VEN TOR MQKWATTORNEY April 10, 1934. A s, CA'SWELL CIRCUIT BREAKER UNIT Filed-July22, 1951 INVENTORQ 5 Sheets-Sheet 5 BY M i- Esfid ATTORNEY.

Patented Apr. 10, 1934 CIRCUIT BREAKER UNIT Arthur .S. Caswell,Philadelphia, Pa., assignor to I-T-E Circuit Breaker Company,Philadelphia, ...Pa., a corporation of New Jersey Application July 22,1931, Serial No. 552,337

10 Claims. (01. 175-298) My invention relates to switching mechanismgenerally, and particularly automatic switching mechanism or circuitbreakers, movable as a unit with its support or mounting, to causesupplemental movable contacts or terminals movaforesaid auxiliarycontacts, adapted upon movement of the unit to engage with and disengagefrom associated contacts, for closing or opening auxiliary or controlcircuits for any purpose, par ticularly for control or operation of theswitching mechanism or circuit breaker, for signalling or the like; theauxiliary contacts of an auxiliary or control circuit remain inengagement with each other and, without substantial alteration of theirposition with respect to each other, follow the movement of the unit toa position in which the aforesaid supplemental contacts separate inremoving the switching mechanism or circuit breaker from its circuit,the continued engagement of the auxiliary contacts permitting for suchposition of the unit testing or other operation of or by the auxiliaryor control circuit; upon further movement of the unit in the samedirection one of the auxiliary contacts is arrested and thereafterremains stationary while its coacting auxiliary contact, carried by ormovable with the unit, separates from it and so opens the auxiliary orcontrol circuit.

My invention is concerned further with the structure of coactingcontacts, more particularly the auxiliary contacts for the control orauxiliary circuits aforesaid.

For an understanding of my invention and for illustration of some of theforms it may take, reference is had to the accompanying drawings, inwhich:

Fig. 1 is a view in perspective showing the front and side of a circuitbreaker unit constructed in accordance with my invention, and with boththe supplemental and auxiliary contacts in disengagement.

Fig. 2 is a side view looking from the rear of the circuit breaker unit.in the same position as shown in Fig. 1.

Fig. 3 shows in plan and elevation the relation of the supplemental andauxiliary contact members in closed, intermediate and full openpositions of the circuit breaker unit.

Fig. 4 is a schematic diagram of a typical arrangement of the circuitscontrolled by the supplemental and auxiliary contacts; and

Fig. 5 shows the details in plan and elevational views of a contactassembly which comprises one of the features of my invention.

Figs. 1 and 2 show a cell comprising a circuit breaker unit supported ina fixed frame in such manner that the unit can be movedin or out toengage or disengage the circuit breaker supplemental cc itacts withcomplementary main 05 stationary c0. :tacts to which are secured themain incoming and outgoing conductors to thereby disconnect the unitfrom the circuits which it controls. The circuit breaker shown is of thesolenoid operated type, and it is necessary for 7 the breaker to becontrolled by and to control auxiliary circuits, such as those foroperating the closing and trip coils, for signalling purposes, and tooperate remote control devices, interlocks, and the like.

In order that the breaker unit may be readily removable for inspection,repair or replacement purposes. it is desirable to have contacts inthese various control circuits which are connected and disconnected bythe same motion which connects and disconnects supplemental contactsfrom the main stationary contacts. In my arrangement the supplementaland stationary contacts may be disconnected, and the auxiliary controlcircuit contacts caused to follow up the movement of the unit so as toremain in their original fixed engagement in an intermediate position ofthe switch in order that the operation of the circuit breaker and theauxiliary circuits and apparatus associated therewith may be testedunder the identical conditions which obtain in service, and yet noteffect a connection to the main incoming and outgoing conductors. In thecircuit breaker described herein there are three conditions available;(1) all'contacts, both supplemental and auxiliary, are engaged in theclosed position of the circuit breaker unit, (2) in an intermediate ortest position the supplemental contacts are disengaged but all thenecessary auxiliary control contacts remain in their original positionof engagement; and (3) in the full open position both the supplementaland auxiliary contacts are disengaged and all circuits are open, and thebreaker unit may be removed or repairs may be safely made since thereare no live circuits remaining on the unit. Referring to Figs. 1 and 2of the drawings, there is shown a fixed framework 1 in which is encloseda solenoid operated circuit breaker mounted on a panel 2 of slate orother insulating material. An insulating stationary panel 3 carries, theblades 4 of the main fixed contacts to which the incoming and outgoingmains or bus conductors (not shown) are connected. The panel 2 carriesthe supplemental contacts 5 (Fig. 2) which comprise rear terminals forthe circuit breaker and which receive the blades 4, and is secured bybolts 6 to a movable angle iron frame '7 supported from the side members8 of the cell framework by two pairs of pantograph links 9 and 9', onepair to each side of the panel. The pantograph links are pivoted attheir upper ends to the stationary and movable frames, respectively,while their lower ends have a slotted connection with the frames, andthe breaker unit may thus be withdrawn and moved towards the front ofthe cell, as shown in Figs. 1 and 2, to give various positions withrespect to the fixed contact panel 3. A screw jacking mechanism 12engages plate 10 which is secured to the lower part of the angle ironframe 7 and reduces the effort required for engaging and disengaging thebreaker unit contacts.

Secured to the back of the circuit breaker panel is a contact base 13carrying the auxiliary control circuit contact fingers 19, 19' and 19".On either end of this base are metal blocks 17 Welded to the frame '7,which carry guide rods 14. Another auxiliary contact terminal base15,.which carries the complementary auxiliary circuit blades 20, 20' and20 is slidably supported by these rods, the compressed springs 16 urgingthe base 15 towards the contact base 13 and normally causing engagementof the complementary auxiliary contacts. The auxiliary. circuit leadsfrom the closing and trip coils and switches mechanically operated bymovement of the main breaker contact arms on the front of panel 2 passthrough to the back of the panel, and are connected to the terminalfingers 19, 19' and 19" on contact base 13 as shown, and the leads fromthe studs 21. 21' and 21" which connect with the complementary auxiliarycircuit blades are gathered into a cable 23 and are led into wiringtrough 24. Portions of the base 15 and the wiring trough are broken awayin Fig. 2

in order to show the spacing of the contact fingers carried by contactbase 13.

The various circuits of the arrangement are shown in Fig. 4. Thesupplemental contacts 5 and fixed contacts 4 control the connection ofthe circuit breaker unit to the incoming and outgoing conductors of thecircuit which the breaker controls. A closing solenoid circuit, a tripcoil and an alarm circuit are also shown, although various otherauxiliary circuits may be and often are used. The circuit breaker shownmay be electrically closed and opened by switches 25 and 26 which are incircuit with the closing solenoid and trip coil, respectively. When thebreaker is tripped either manually, or by abnormal circuit conditions,or by remote control switch 26, the switch 2'? which is mechanicallyoperated by movement of the main breaker contact arms is caused to opento break the circuit of the tripping coil, and the switch 28 is closedto complete the circuit of the alarm signal 29.

The operation of the circuit breaker unit is as follows: In the closedposition all contacts are in engagement as shown in Fig. 3(a). As thecircuit breaker unit is withdrawn, the supplemental contacts aredisengaged because the panel 3 supporting the blades 4 is stationary,whereas the panel 2 carrying the supplemental contacts 5 is withdrawnwith the breaker unit.

The male auxiliary contact terminal base 15, however, follows up thebreaker panel by the urging of springs 16 and maintains the originalfixed engagement of auxilary contacts 19 and 20, thus'making contactfrom the closed position of the breaker to the intermediate or testposition shown in Fig. 3(1)), after the supplemental con tacts havedisengaged and are separated by a safe distance. In this manner, therelative positions of the auxiliary contacts have not changed, but stillretain their original fixed contact relation. In this position theoperation of breaker and the auxiliary circuits may be observed underservice conditions, but without disturbing the main circuit controlledby the breaker. At the intermediate position, however, stops 18 whicharesecured to either side of the terminal base 15 abut against the framemembers 8, thus preventing further outward-movement of the base 15.Continued movement of the breaker panel therefore separates theauxiliary contacts because base 13 continues to follow up the panel.Figs. 3 (c) and (d) show plan and elevational views of all the contactsin the full open position of the breaker unit.

The auxiliary contacts are preferably of the type shown in Fig. 5, inwhich the contacts are shown in normal engagement in the elevational andsectional views of (a) and (b), and in disengagement in (c). The view of(d) illustrates the flexibility of the contacts when in misalignment,and (e) is a detail of the supporting bracket. The contact assemblycomprises a female metal contact support or bracket 33 secured to theinsulating'base 13, the bracket being formed in the shape of a squarecornered U with its open end towards the base. An extension of one end34 acts as a dowel in a hole in the base while the other end is tappedto receive the fastening machine screw 32, which also serves as abinding post for connecting control wires. The central portion of thebracket has an opening defined by the arcuate edges 35 through which thecontact leaves or fingers 19 pass to receive the male blade 20. Thesecontact leaves are duplicates placed in opposed relation and formed sothat they will rock or rotate about the edges 35 of the bracket. Theinner ends of the contacts are offset from the center line with parallelend portions 38 against which the compressed contact spring 37 exertsits pressure, and since the leaves are fulcrumed on the arcuate edges 35the pressure of spring 37 causes good contact to be maintained with thesupport 33 and the inserted blade 20.

The outer ends 38 of the contact leaves have a wide fiare for easyentrance of the blade, while at the end of this fiare the contacts aretangent to each other and then diverge by reason of the opposing concaveportions forming a pocket between the' contact point and the hingepoint. This design allows a considerable variation in the relativeposition of the male blade without interfering with the efficiency ofcontact as shown in Fig. 5 (d). The motion about the hinge is limited bythe lugs 36 which are formed with the piece 33.

The male or blade contact consists of a fiat bar of metal bent into theshape of the letter L. The shorter leg is pierced for receiving thescrew 21 which secure it to the base 15 and also serves as a bindingpost. The longer leg extends at right angles to the base forming thecontact the breaker blade 20, the outer edges of which are chamfered foreasy entrance into other contact. An extension of the blade acts as adowel 44 which fits in a hole in the base and prevents the contact fromturning.

., In the foregoing construction, due to the freedom of movement of thecontacts in a vertical, horizontal and rotational direction, thecontacts will automatically align themselves with the male blade uponinsertion of the latter,'and will give the same contact area and thusthe same electrical connection whether the contacts are in alignment, orare misaligned within wide limits. Also, by providing a suificientclearance between the contacts 19 and the opening defined by the arcuateedges 35, either of the contacts may be removed through the openingwithout disturbing the electrical connections to the bracket, and thuspermit of ready cleaning or replacement of the contact fingers which arethe usual source of trouble in a switch.

What I claim is: I

1. Switching mechanism comprising a circuit breaker unit havingsupplemental contacts in engagement with fixed bus contacts andauxiliary circuit contacts in fixed engagement, means for causingdisconnection of the supplemental contacts in a position of the breakerunit intermediate its closed and full open positions, means for causingthe auxiliary contacts to follow up the movement of the breaker unit tothe intermediate position to prevent disengagement of the auxiliarycontacts, means for disengaging the auxiliary contacts in full openposition of the breaker unit and for causing their reengagement when thebreaker unit is returned to the intermediate position, said auxiliarycontacts comprising opposing tongues and a cooperating blade forengagement or disengagement therewith, the said tongues adapted at oneend to receive the blade, and having their other ends positioned withina supporting bracket and spaced apart by spring means, the tonguespassing through the opening in said bracket to receive the blade, thetongues being flexibly mounted to permit horizontal, vertical, androtational misalignment of the tongues or blade.

2. Switching mechanism comprising a circuit breaker unit havingsupplemental contacts in engagement with fixed bus contacts andauxiliary circuit contacts in fixed engagement, means for causingdisconnection of the supplemental contacts in a position of the breakerunit intermediate its closed and full open positions, means for causingthe auxiliary contacts to follow'up the movement of the breaker unit tothe intermediate position to prevent disengagement of the auxiliarycontacts, means for disengaging the auxiliary contacts in full openposition of unit and for causing their reengagement when the breakerunit is returned to the intermediate position, said auxiliary contactscomprising oppositely disposed contact fingers and a cooperating bladefor engagement or disengagement thereprising a fulcrum for the bladeswith such clearance that the blades have a limited, horizontal,vertical, and rotational movement whereby the fingers will alignthemselves with the blade upon insertion of the latter.

3. Switching mechanism comprising a circuitbreaker, supporting structuretherefor movable to dsconnect the circuit-breaker from its circuit,auxiliary circuit-contacts carried by said movable supporting structure,and means for effecting separationof said auxiliary contacts uponmovement of said structure from in-circuit position of the circuitbreaker beyond an intermediate position for which the circuit-breaker isout of circuit.

4. Switching mechanism comprising a circuitbreaker, movable supportingstructure therefor, structure for supporting bus contacts adapted to beengaged by supplemental contacts carried by said movable supportingstructure, relatively movable auxiliary-circuit contacts, carried bysaid movable supporting structure, means movable with said movablesupporting structure tending to maintain said auxiliary contacts inengagement, and means for effecting separation of said auxiliarycontacts when said movable structure is moved beyond a position forwhich said supplemental contacts are out of engagement with said buscontacts.

5. Switching mechanism comprising a circuit breaker unit, movable todisengage contacts movable therewith from bus contacts, auxiliarycontact structure mounted in fixed position upon said breaker unit,complementary auxiliary contact structure carried by saidcircuit-breaker unit and movable relative to said auxiliary contactstructure, and means effective upon' movement of said unit beyond aposition effecting disengagement of said bus contacts and saidfirst-named contacts to efie ctseparation of said auxiliary contactscarried by said circuit-breaker unit.

6. Switching mechanism comprising a circuit breaker unit, movable todisengage contacts movable therewith from bus contacts, auxiliarycontact structure mounted in fixed position upon said breaker, structuresupported by sa'd unit for movement relative thereto, complementaryauxiliary contacts carried by said structure, and means for restrainingsaid structure from movement with said circuit-breaker unit beyond aposition effecting disengagement of said bus contacts and saidfirst-named contacts to effect separation of said auxiliary contacts.

'7. Switching mechanism comprising a circuitbreaker mounted on a panelcarrying contacts on the rear thereof and movable to effectdisengagement with bus contacts, relatively fixed and movable auxiliarycontacts mounted from the rear of said panel, and means for effectingseparation of said auxiliary contacts carried by said panel when saidpanel is moved beyond an intermediate position for which said buscontacts and said firstnamed contacts are disengaged.

8. Switching mechanism comprising a circuitbreaker mounted on a panelcarrying contacts on the rear thereof and movable to effectdisengagement with bus contacts, fixed auxiliary contacts mounted on therear of said panel, guide structure extending from the rear of saidpanel, a member guided thereby and carrying complementary auxiliarycontacts, means for basing said member to a position effectingengagement of said auxiliary contacts, and means for restrainingmovement of said member with said panel, as said panel is moved beyondan intermediate position for which said bus contacts and saidfirst-named contacts are disengaged, to eiTect separation of saidauxiliary contacts.

9. Switching mechanism comprising a circuit breaker, a cell therefor,supporting structure for porting the circuit-breaker panel within saidcell and permitting movement of said circuit-breaker toward the front ofsaid cell to disconnect it from its circuit, auxiliary contacts carriedby the circuit-breaker panel and remaining in engagement for forwardmovement of said linkage to an intermediate position beyond itscircuit-breaker disconnect position, and means for effecting separationof said auxiliary contacts upon forward movement of said linkage beyondsaid intermediate position.

ARTHUR S. CASWELL.

